BW 4405 Rebuild Questions

[Rleedude]

Daughter's 2000 Explorer (125K miles) started having ratcheting sound when decelerating and it was determined that the issue was most likely with the transfer case. Research seemed to point pretty clearly at the same issue that Glacier991 covered in his helpful 2007 diary.
Opened it up and the found that the shift fork, including the nylon guide pads, seemed fine except the little roller shaft seems to be bent downward with the rear case halve off.

The helical cam has some "wear damage" (??) that appears to have been caused by the roller of the shift fork.

The primary damage seems to be to the back end of the hi-lo collar/gear.

I'm assuming this is what was making the ratcheting noise on decel.

Glacier991 and others here and elsewhere have determined that the damage is caused by the "ovaling" of the bores on both case halves that the rod for the shift fork rides on. I expected to see this "ovaling", but do not. There is some play at the mouth of the bores, but none that I can tell at the base. I reconnected the two case halves with the rod sandwiched in place and left a gap just large enough to push a slim jim (car lock opener) in there and could not get any lateral movement out of the rod in any direction. With that in mind...I'm left with wondering what else might cause the damage??
As Glacier991 suggested, the roller wheel on the shift fork does not seem to engage the cam as much as one would expect, but I don't know if that could cause this.
The rest of the parts appear to be in great condition.
Were this my truck, I would have taken it to a shop and paid the $1,500 to have a re-man put in. But since it's my daughter's, I'm trying to save her some money.
None of the transmission shops I contacted worked on them...they just replace with re-manufactured ones, but one of them suggested replacing the cam and the collar and putting it back together...and I'm inclined to agree with them, but there's still that nagging concern of what's the cause?

1) Is it possible for the gears on the collar to get jacked up without the ovaling of the rod bores?
2) I assume vibration (since the roller on the shift fork doesn't rotate) over time caused the wear in the cam...could that be the cause of the damage to the collar?
3) Should I get the Omega shift fork that has the longer roller?
4) Out of curiosity, what is the "tone ring" for? It appears to be a "gear to nowhere"??
5) How tight should the chain be? It's hard to tell when the case is apart, but it seemed to have maybe 1/4" play when I had the case back together for my rod lateral movement test.
6) There was no gasket, but RTV between the case halves...would this indicate that the TC had previously been worked on?
7) Big Question...Does anyone think that replacing the shift fork (Omega), cam and collar is a bad gamble?

Thanks to all who have posted on the topic in the past...this forum is one of the rare redeeming values of the internet!

 

[JK080]

The fork roller is beat into the cam when the hub slipped out of the teeth inside the gear in the planet (ratcheting sound). This caused the dents and bent the roller.

I have always installed the bushings in the case for the shaft and replaced the fork with a one with a better roller.

Even if the case didn't look too worn out.

 

[Rleedude]

Sounds reasonable JK080, thanks for the input.
It would have been nice to know what actually caused it to do that, but oh well!
I ended up replacing the shift fork with the improved Omega version along with the cam and collar. Seems to be working fine, but I reckon time will be the real test.
A couple things I learned along the way:
- One or two of the bolts that attach the TC are tough to get at...be prepared to be patient.
- Air ratchets are a huge plus with this one.
- The TC is pretty heavy. I read where some put it on their chest...I didn't have the vertical clearance for that, but don't think I would have tried even if I had. I used a floor jack when removing, but that proved to be a poor choice as the TC has no balancing point in any direction. Fortunately no damage was incurred to the TC or bodily parts. To reinstall I ended up using a floor jack and a combination of a wooden furniture dolly and 4x4's to raise it as high as I could then got an arm under it and prayed like crazy that I could stab it on the transmission spline before my arm gave way. I succeeded, but my shoulders won't be happy at me for along time. Lesson learned...ask a friend to give you a hand or borrow someone's transmission jack.
- This should have been a no brainer, but I didn't think about losing trans fluid...it kept draining and draining...3 quarts out of the 5 it holds.
- I would recommend draining the fluid from the TC case prior to removal. BTW... the TC case holds a little under 2 quarts of ATF. I think it calls for Dexron III...I used synthetic Royal Purple Max ATF.
- One of the most frustrating parts of the project was removing the 30mm nut that attaches the rear drive flange. Most guys said theirs came off easily with an impact. I think I need a better impact wrench cuz mine couldn't break it even after soaking it overnight with penetrating oil and taking a torch to it. I ended up fashioning a bar that attached to the flange to keep it from turning and laid the TC on its side on the ground and took a 15lb sledge to the 1/2" breaker bar with a 1 1/16" socket. Might have been easier before removing the TC from a stable truck??

Grateful daughter makes it all worth it!